Socio-economic and even political considerations often become
extremely important in accentuating the problems of land degradation through
salinization, sodication and related processes. Such factors are often beyond
the control of individual farmers and for this reason appropriate policy
decisions and corrective measures become the responsibility of respective
governments. Some of the more important factors are discussed below.

7.1 Faulty irrigation
schemes

The introduction of irrigation is often considered a solution
to the pressing problems of the arid and semi-arid regions. However, there are
numerous examples of soils degraded and lost to production due to ill conceived
or poorly implemented irrigation schemes. The most serious problems in
irrigation development do not relate to the storage and delivery of water but to
the secondary effects of irrigation.

According to an FAO study there has been a galloping inflation
in the cost of land and water resources development. Thus the development cost
of surface irrigation, including storage dams, drainage and on-farm works per
hectare increased from US $500 to 2000 in 1970/71 to more than US $10 000 in
1980. This figure is likely to increase further in the future as the easier and
simpler projects are completed leaving the increasingly difficult projects.
Because of the high costs involved to make the irrigation projects operational,
there is a tendency to find only the money required for the rapid establishment
of irrigation facilities in order to grow marketable crops quickly and to defer
or omit drainage works in the hope that either they will not be required or that
the necessary funds will be found when the project is producing a profit.
Unfortunately, the cost of providing drainage and reclamation when the problems
of waterlogging and salinity have already appeared are much more, apart from the
huge losses already incurred through partial or complete loss of production of
many areas. For any lasting success, all irrigation projects need sound drainage
networks considering soil, climatic, geohydrological and geochemical factors as
also the social and economic setting of the region. If the drainage networks are
put into operation at the same time as the water supply from canals, a great
saving will ultimately result to the project.

In practice, the time gap between the start and completion of
a major irrigation project may normally extend to over 10 to 15 years. Often the
increased costs during this period result in spending the entire project money
on the construction of storage works, main and secondary canals, leaving little
or no money for investment in on-farm irrigation development. As a
result, a sizable portion of the water delivered to the farms is wasted due to
irregular distribution within the farm, deep percolation losses below the root
zone and surface evaporation during application (Plate 13). This results in the
development of a high water table and salinity problems much sooner than
anticipated. This calls for appropriate allocation of money within the project
funds for on-farm water management including lining of field
channels and water courses to prevent seepage losses, proper land shaping, field
layouts for uniform water application, etc.

7.2 Extensive vs. intensive
irrigation

Water resources being limited, a choice has always to be made
whether to bring a relatively small area under intensive irrigation, i.e. to
grow two or more crops in a year or to adopt a protective type of irrigation on
a large area. In theory, concentrated watering, considering the water
requirements in an intensive cropping agriculture along with provision of
adequate drainage, will be more conducive to the control of salts in the root
zone. In practice however, when irrigation projects are planned there is a
tendency to bring more area under irrigation than the available water resources
would permit under an intensive agriculture. This is done for political and
largely social reasons. For example, in India although it has been realized that
concentrated efforts to irrigate areas with the most favourable climate and soil
and topographical conditions would cost less and would give substantial
increases in production, it would at the same time amount to postponing
irrigation indefinitely in areas where the agricultural population is living on
subsistence agriculture with the perpetual hazards of drought and other vagaries
of nature. For this reason the government has adopted a judicious combination of
extensive and intensive irrigation since the national policy is to reduce the
economic gap between one section of the people and another, and also to minimize
regional imbalances. Spreading water over a wide area often leads to speeding up
the rate of salinization without eliminating the rising groundwater table. This
is so because insufficient water is available to meet both the crop water
requirements and the leaching requirements for the control of salts in the root
zone.

7.3 Deforestation

Human interferences resulting in indiscriminate and
large-scale deforestation in recent years has been an important factor that has
resulted in altering the water balance of large areas, in many cases resulting
in serious salinization problems both in the irrigated and unirrigated areas.
Unfortunately this fact has not been taken seriously and this is the reason for
lack of systematic studies to evaluate the magnitude of the problem in many
developing countries. Australian work has shown that reduced evapotranspiration,
which is common when the native forests are converted to agriculture involving
non-irrigated annual crops, may result in a build-up of the water table. In one
study it was estimated that the increased recharge to groundwater due to a
change from native woodland and forest to dry farming ranged from 23 to 430 mm
per year (Peck, 1975). Such an alteration in the groundwater balance disturbs
the distribution of salts and has resulted in widespread salinization problems
in many parts of the world. The solutions to the problem appear complex but most
include rational land use aimed at partly restoring the original hydrologic
balance together with site treatments which must be chosen in accordance with
local conditions.

7.4 Water pricing

Existing water laws and water pricing systems are yet another
factor determining the efficiency of on-farm water use. In most developing
countries irrigation is supplied free of charge, although in some taxes are
levied to mobilize resources for financing irrigation works. The farmers who
operate their own pumps or buy water from pumps owned by others must pay for the
amount of water they use. The water use efficiency of such farmers is therefore
much higher than that of those who do not pay for water. The latter case has
resulted in farmers using quantities of water in excess of that required to meet
the crop consumptive use causing the problems of waterlogging and salinization.
Although it might entail many difficulties, a change in the policy to charging
for the water used will help increase over-all water use efficiencies and
control salinity.

7.5 Size of holding and land
consolidation

In many countries the land holdings are small and spread over
a wide area. As a result, the attention of service agencies is diffused and much
time and effort has to be concentrated on encouraging proper management of
inputs by farmers. Land fragmentation and associated differences in cropping and
management help the spread of secondary salinization. Differences in cropping
patterns and irrigation regimes between adjacent farmers will cause migration of
salts from high to low spots, from crop areas with more frequent irrigations to
those with less frequent and from relatively wet soils to relatively dry soils.
Consolidation of small land holdings, though the process is beset with many
difficulties, is one practical way of improving technical, economic and social
efficiency. Figure 41 presents the layout of a 120 ha pilot project area before
and after land consolidation (Sinha and Borah, 1980). Out of 120 ha, only 97 ha
were consolidated, the remaining 23 ha being left unconsolidated for comparison.
The average size of the holdings in the project area before development was 0.35
ha, the sizes varying from 0.05 ha (minimum) to 3 ha (maximum); the individual
plots were scattered and were still smaller, to the extent of 0.01 ha. The
consolidation of land on a scientific basis was found essential for ease of
water management and other agricultural operations. Therefore, after the
acquisition of the land, it was micro-levelled to locate natural ridges and
valleys along which the field channels and water course could be aligned. When
the construction of channels and drains was over, plots were divided according
to the holdings of the farmers in such a way that each plot had a direct access
to the water course, the drain and farm land. Table 46 shows a very significant
and interesting comparison which proves the usefulness of the consolidation of
holdings.

Table 46 COMPARATIVE FIGURES OF ON-FARM DEVELOPMENT WORK
WITH AND WITHOUT CONSOLIDATION OF LAND HOLDINGS (Sinha and Borah,
1980)

Item

Without Consolidation

With Consolidation

Length of irrigation channel (m/ha)

140

85

Length of drains (m/ha)

153

140

Length of roads (m/ha)

37

60

Distance of remotest plot from the irrigation channel
(m)

50.8

Negligible

Distance of remotest plot from the field drain (m)

50.6

Negligible

Area occupied by the channels and drains (% of the field
area)

4.7

3.8

Area occupied by roads (% of the field area)

1.00

1.55

Length of field bunds (m/ha)

1 000

375

When the holdings are fragmented or of small size and
irregular shape, on-farm development without land consolidation is difficult,
inefficient and expensive. Furthermore, the supply of water to each farmer and
draining the land after rainfall and irrigation poses problems. Besides
efficient water distribution and land shaping, land consolidation simplifies
land use planning and helps cut down the time required for water to travel among
plots. It also reduces the length of water courses and farm drains as the land
used in boundaries is reduced when there is consolidation.

7.6 Land tenure system

The land tenure system can also play an important role in the
spread of salinity. Many cultivators in developing countries, such as India and
Pakistan, are share-tenants who are often moved around by the landlords to
different plots each year. As a result the cultivators nave little interest in
protecting the soil from degradation due to salinity or-other factors. On the
other hand, long-term tenancy or private ownership of land will offer incentives
for conservation measures including control of salanization.

7.7 Role of appropriate
technology

Extreme pressure on land resources and the ever-growing need
to produce more food for the increasing population require that the
salt-affected soils be restored to productivity and effective steps taken to
prevent desertification of new areas being brought under irrigation at huge
cost. To accomplish this, it is necessary to develop appropriate technologies
suited to a particular region or country. By the term technology is
meant the whole range of management practices that go into farm production in
such areas. This includes the method of land preparation, best suited crops,
varieties and cropping sequences, their fertilization and best suited cultural
practices including planting techniques, best suited irrigation, drainage and
on-farm water management practices, need of amendments, etc. And the term
appropriate implies that the technologies are relevant and adaptable
down to the farmers level. In the context of developing countries the
technologies developed, in general, must:

- be relevant to the development of the
majority- be based on low levels of investment- be ecologically sound- be based primarily on local resources and skills- have high employment potential- be in harmony with rural traditional cultures, and- be able to contribute to the self-reliance of the rural
economy.

To illustrate this, although the basic principles involved in
the reclamation and management of salt-affected soils are now well understood,
the adoption of advanced technologies in an economically less advanced country
may be difficult without overall economic development and an improvement in the
level of education of the people. Thus, what might be possible for a farmer in
the arid parts of California, USA, or in Australia by way of water management
might be completely out of reach of the cultivators in arid Rajasthan in India.
For example, in theory, while it is now well established that greater efficiency
of water use and salt leaching can be accomplished by the adoption of sprinkler
irrigation, for economic reasons it might be impossible to adopt this method
over wide areas in most developing countries. And even if the economics
permitted it, the adoption by illiterate farmers of such sophisticated water
control equipment will present difficulties when it comes to maintenance, etc.
As an example of the latter, in the past decade or so, millions of dollars have
been invested in providing modern subsurface drainage systems in Iraq with the
aim of restoring productivity to the land that has gone out of cultivation due
to salinization. Iraqi farmers have had little or no experience with such
drainage methods and are generally ignorant of them. A well designed and
operated drainage system can greatly increase the productivity of irrigated
agriculture but only if it is effective down to the farmers fields. The
individual farmer must understand the importance of drainage. His full
cooperation is necessary to maintain the field ditches and interception drains
to ensure the functioning of the costly drainage system. Thus, in order to
achieve the desired objectives of increased food production from these areas, it
will be absolutely necessary to elevate the overall level of education of the
farmers (Allahwardi, 1979).

It is apparent, therefore, that if technology for the
reclamation of salt-affected soils and for the prevention of the spread of
salinity is to be effective and lead to continuous improvement in food
production, it is essential that:

- relevant farming technologies for such areas be
developed to meet realistic goals considering the social, economic and political
setting on the one hand, and tradition and level of education of the farmers on
the other;

- there is a continuous effort to improve upon the
technologies as more scientific knowledge and experience is gained and as the
economic conditions become more favourable.

New or existing technology must be tailored to meet local
conditions and this can best be accomplished by teams of scientists who are well
aware of the constraints operative at the farmers level. In other words,
relevant research conducted by scientists who appreciate the social, cultural
and political aspects of the country and who can guide team efforts towards the
best solutions under the realities with which the farmers work. Research
programmes of the necessary magnitude must be organized so as to provide
continuous support to the field programmes aimed at improving the existing
methodologies of reclamation and on-farm water management practices.

7.7.1 Testing the technologies

Scientific technology for the reclamation and management of
salt-affected soils and for improved on-farm management practices must be tested
on a pilot project scale before being transferred on a large scale to the
farmers fields. The objectives of such a pilot project should
include;

- testing and demonstration of the new or existing
technologies on the farmers fields;

- modification of the technologies to suit the local
conditions, if required;

- critical calculation of the profitability and economics of
the new technologies;

- identification of bottlenecks in the transfer of technology
whether they are of a technological, socio-economic or administrative
nature.

Only well tested technology with proven benefits should be
passed on to the farmers. Pilot projects also serve to define the
infrastructural needs and the various likely impediments in the transfer of
technology. For example, while land shaping and levelling are the important
components of any project aimed at improving the on-farm water management, many
farmers do not have adequate resources and do not own the required implements
and machinery required for this. Experience gained in the pilot project must
define a strategy to accomplish this. Reclamation of sodic soils requires
application of amendments. How can availability of the amendments to the farmers
be ensured at appropriate cost? Should there be an element of subsidy? If yes,
are institutional finances available or can they be mobilized?

Often the solution to a salinity problem may lie outside the
capability of a single farmer or even a group of farmers. Such is the case where
natural drainage channels do not exist to allow the salt-laden drainage waters
to be disposed of. Under such circumstances a central drainage facility or an
evaporation pond area may have to be developed if the salinity problems of the
area are to be solved. Sometimes it is helpful to use pumped groundwater for
irrigation, particularly when the groundwater has low total salinity. This
provides not only a source of irrigation but also acts as an effective drainage
measure (Narayana et al. 1977; You and Wang, 1983). If the farmers are advised
to install the wells, do they have the resources; what are the alternatives? If
particular crops or crop varieties are recommended for adoption in an area, how
can the availability of good seeds to the farmers be ensured? If it is intended
to introduce or recommend new crops to be grown in an area for reasons of
greater tolerance to salinity or sodicity conditions, are there adequate
marketing facilities for the produce? Workable answers to these and several
other questions that arise at the testing stage must be arrived at so that when
large-scale programmes are taken up, they are effective.

7.8 Extension and farmers
education programmes

Irrigation farming calls for particular skills in the
application of water and the tillage of irrigated soil if its great potential
for increased productivity is to be developed and sustained. The efficiency of
irrigation schemes rests, in the final analysis, on the individual cultivator
who is the most important link in the chain of production. When irrigation is
introduced in a new area the farmers of the region have had little or no
experience in handling large quantities of water on the farm. Since the
cultivator may be tradition bound and lack the benefit of education, effort and
ingenuity must be applied to convert him into an efficient irrigator. To ensure
steady progress in irrigation methods and water use efficiency the farmer must
be kept informed of new ideas through organization of appropriate training and
other extension programmes. Well designed and operated irrigation and drainage
systems can increase the productivity of irrigated agriculture but only if they
are effective right down to the farmers field. The individual farmer must
understand the importance of land shaping and uniform water application, the
need and desirability of irrigating crops based on available scientific
information, the importance and best ways of maintenance of field, channels
including proper lining procedures, best methods for control of weeds in
irrigation and drainage channels, etc. A continuous effort to elevate the level
of education of the cultivator will result in enhanced capability to manage the
land and water resources with minimum degradation through salinization and
related phenomena.